Protective Efficacy of the Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes), from India in Neuronal Hippocampal Cells against Hypoxia.

This study demonstrated the protective efficiency of extracts of the Indian variety of Ophiocordyceps sinensis (=Cordyceps sinensis) (CSEs) in HT22 (murine hippocampal) cells under hypoxic conditions. Various parameters such as cell viability, reactive oxygen species, levels of endogenous antioxidants, inflammatory cytokines, transcription factors, and oxidation of macromolecules were analyzed. In addition, the radical scavenging abilities of hydroxyl radicals, nitric oxide, and superoxide radicals were also studied. Antioxidant compounds, ascorbic acid, hesperidin, and rutin were quantified by high-performance thin-layer chromatography. The information acquired from high-performance thin-layer chromatography profiling was subjected to principal component analysis for data clustering. Findings of this research revealed that ascorbic acid and rutin were highest in aqueous CSE, whereas the maximum amount of hesperidin was found in 25% alcoholic CSE. In vitro studies showed that all the CSEs protected HT22 cells well by upregulating the level of endogenous antioxidants and preventing the oxidation of lipids and proteins. These extracts also reduced the amount of hypoxia-induced inflammatory cytokines and transcription factors on par with the normoxic control with more or less equal protection in the cells under hypoxia, and indicated significant radical scavenging potential.

Survival response of hippocampal neurons under low oxygen conditions induced by Hippophae rhamnoides is associated with JAK/STAT signaling.

Janus activated kinase/signal transducers and activators of transcription (JAK/STATs) pathway are associated with various neuronal functions including cell survival and inflammation. In the present study, it is hypothesized that protective action of aqueous extract of Hippophae rhamnoides in hippocampal neurons against hypoxia is mediated via JAK/STATs. Neuronal cells exposed to hypoxia (0.5% O2) display higher reactive oxygen species with compromised antioxidant status compared to unexposed control cells. Further, these cells had elevated levels of pro-inflammatory cytokines; tumor necrosis factor α and interleukin 6 and nuclear factor κappa B. Moreover, the expression of JAK1 was found to be highly expressed with phosphorylation of STAT3 and STAT5. Cells treated with JAK1, STAT3 and STAT5 specific inhibitors resulted in more cell death compared to hypoxic cells. Treatment of cells with extract prevented oxidative stress and inflammatory response associated with hypoxia. The extract treated cells had more cell survival than hypoxic cells with induction of JAK1 and STAT5b. Cells treated with extract having suppressed JAK1 or STAT3 or STAT5 expression showed reduced cell viability than the cell treated with extract alone. Overall, the findings from these studies indicate that the aqueous extract of Hippophae rhamnoides treatment inhibited hypoxia induced oxidative stress by altering cellular JAK1, STAT3 and STAT5 levels thereby enhancing cellular survival response to hypoxia and provide a basis for possible use of aqueous extract of Hippophae rhamnoides in facilitating tolerance to hypoxia.

Cordyceps sinensis increases hypoxia tolerance by inducing heme oxygenase-1 and metallothionein via Nrf2 activation in human lung epithelial cells.

Cordyceps sinensis, an edible mushroom growing in Himalayan regions, is widely recognized in traditional system of medicine. In the present study, we report the efficacy of Cordyceps sinensis in facilitating tolerance to hypoxia using A549 cell line as a model system. Treatment with aqueous extract of Cordyceps sinensis appreciably attenuated hypoxia induced ROS generation, oxidation of lipids and proteins and maintained antioxidant status similar to that of controls via induction of antioxidant gene HO1 (heme oxygenase-1), MT (metallothionein) and Nrf2 (nuclear factor erythroid-derived 2-like 2). In contrast, lower level of NF κ B (nuclear factor kappaB) and tumor necrosis factor- α observed which might be due to higher levels of HO1, MT and transforming growth factor- ß . Further, increase in HIF1 (hypoxia inducible factor-1) and its regulated genes; erythropoietin, vascular endothelial growth factor, and glucose transporter-1 was observed. Interestingly, Cordyceps sinensis treatment under normoxia did not regulate the expression HIF1, NF κ B and their regulated genes evidencing that Cordyceps sinensis per se did not have an effect on these transcription factors. Overall, Cordyceps sinensis treatment inhibited hypoxia induced oxidative stress by maintaining higher cellular Nrf2, HIF1 and lowering NF κ B levels. These findings provide a basis for possible use of Cordyceps sinensis in tolerating hypoxia.